Electric annealing apparatus



Nov. 13, 1951 w. J. WILLENBORG ELECTRIC ANNEALING APPARATUS Filed May 6, 1950 INVENTOR. W /e/26o Wa He! J.

Patented Nov. 13, 1951 UNITED STATES PATENT OFFICE 8 Claims.

This improvement relates to apparatus for t and method of electrically annealing metals and particularly to means for annealing collapsible metal tubes, such as used for toothpaste, shaving creams and the like. In this disclosure the annealing of aluminum collapsible tubes is particularly described, although the tubes may be made of other metals or compositions, but the improvement is applicable to various other devices.

In the prior art the tubes have been passed through an oven which is heated by electricity or is fired by oil or gas. The oven temperature and the rate of movement of the tubes through the oven are controlled to properly anneal the tubes. In the present improvement the proper heating of the metal to be annealed is accomplished by passing an electric current through the metal at the proper current value and for a suitable interval of time. Metals which have a positive temperature coeflicient of resistance increase in resistance with increase in temperature and thus aid in the heating of the metal by the increase in resistance.

The main object of this invention is to provide a simple method and apparatus for electrically annealing metals by passing an electric current therethrough. A further object is to pass a comparatively heavy electric current through the metal or tube for a short interval of time so that the annealing may be rapidly and efiiciently accomplished. A further object is to provide controlling apparatus which will automatically insure the proper current value and timing of the passage of current which will result in the proper annealing of the particular device selected. Another object is to utilize the annealing current from the source in such a manner as to avoid any lag of current in attaining its proper annealing value and to avoid interfering with the regulation of the current source. Other objects and advantages will be understood from the following description and accompanying drawing illustrating embodiments of this invention in its application to the annealing of aluminum collapsible tubes.

Fig. l is a diagram showing the method and apparatus with controls of the application and timing of the current; Fig. 2 is a diagram showing controls wherein the collapsible tube is automatically placed in position, then automatically annealed and then removed and replaced by another tube; and Fig. 3 is a plan view of the clamping rings.

Referring to Fig. l, a source l is indicated for supplying the annealing current to the lines 2 and 2a. When the annealing current is not passed through the tube, it is supplied to a load 3 which load is adapted to consume a current ich s a proxima e equa to h an lin current when passed through the tube. This load is indicated as adjustable for the purpose of changing the current consumption to a value corresponding to that desired for the annealing.

The tube 4 is indicated of the form after it has been drawn from the aluminum metal and is in the form of a cylinder with an open lower end and a top portion of heavier metal with an extended end for receiving the cap. The cylindrical portion of the tube is hardened in the drawing process and it is that portion which requires annealing for making the metal flexible for convenient use. By this improvement the tube portion is quickly and uniformly annealed. The tube is indicated in the position to be anuealed with a circuit connection from its upper end to a fixed contact 5a of a relay 5 having a pivoted armature 5b which is electrically connected to the line 2a. The lower end of the tube is electrically connected to the line 2a at the other side of a break in the line 2a which break is adapted to be by-passed by the pivoted armature ab controlled by a relay 6 having a fixed contact 5a. When the relay 6 is deenergized, it engages the constact 6a and closes the break in the line 2a.

In the lower part of Fig. l a timer and circuit controller are indicated for periodically energizing the relays 5 and 6 in proper sequence. A source of current 1 supplies the lines 8 and 8a. A motor 9 is supplied with current from the lines 8 and 8a and drives a pair of timers l0 and H. Each of the timers is shown as having four projecting portions apart. The outer portions of the projections may be of insulating material as indicated, or the timers themselves may be made of insulating material. Above the timer ID is shown a pivoted contact arm l 06!. which is adapted to engage a fixed contact I012 when suiiicientl raised by each of the projecting portions of the timer Ill. Similarly a pivoted conducting arm I la is adapted to engage a fixed contact Ilb when sufiiciently raised by each of the projecting portions of the timer I I. The fixed contacts lb and Nb are electrically connected to the line 8. The movable contact Illa is electrically connected to the winding of the relay 5 with a return connection to the line 8a. The movable contact Ila is electrically connected to the winding of the relay 6 from which a return wire is connected to the line So.

1 shows the parts in condition when no current is passing through the tube 4, the contact ifla being out of engagement with the contact lilb with the result that the relay 5 is deenergized. At this time the relay 6 is deenergized resulting in the relay contact 6?) engaging the fixed contact 6a and thereby closing a direct path from the source I to the load 3. When the timers are rotated somewhat in the direction indicated by nealing the tube.

we a? the arrows, the contact Ilia is first raised to engage its contact 10b and thereby energizes the relay and causes its contact 5?) to engage the fixed contact 5a. This closes a path from the line 2a through the tube t and then to the line 2a which places the tube in parallel with the closed relay contacts 6a and 6b. Upon further movement of the timers, the contact I la is raised to engage the fixed contact lib by the passing of a projection of the timer I! under the contact element Ila. This energizes the relay 6 and opens the shiuit or by-pass around the circuit of the tube 4 which results in the tube being subjected to the current which passes through the load 3. This heavy load current continues through the tube 6 for a short period of time after which the projection on the timer I l passes from under the contact I la which then separates from the contact Ill) and deenergizes the relay 6 which closes its by-pass and thereby short-circuits the current passed through the tube 4. Further movement of the timers results in the contact Illa being released from its contact lfib which deenergizes the relay 5 and thereby opens the circuit through the tube 4-. The parts are then in the relative positions assumed at the beginning of the cycle. The tube 5 may then be removed from the circuit and replaced by another tube to be annealed after which the cycle is repeated by the continued movement of the timers.

This cycle comprises passing a current through a load and through a switch, then connecting the device to be annealed in series in the load circuit and in parallel with the switch, then opening the switch to cause the load current to pass through the device for a proper time interval for the annealing, then closing the switch for shunting or by-p-assing the load current from the tube, and then opening the circuit of the device for permitting its removal and replacement.

The timing mechanism which controls the energization and deenergization of the relays 5 and 6 insures the above sequence of control by the contour of the timers Ill and II and their relationship to each other. The time interval when the relay 5 is deenergized and the relay 6 is deenergized is suificient for enabling the treated tube to be removed and another one inserted in its place. It is apparent that the load circuit is never open and that the current flow is approximately constant which insures an initial application of full current strength to heat the tube to the annealing temperature and, of course,

the timing mechanism insures a proper time interval of the heating current for properly an- The amount of current flow through the load 3 and through the tube when being annealed, is determined by the size of the tube and the length of time required for annealing. The greater the current passed through the tube, the less will be the time required for properly annealing the tube within practical operating limits. The source I is of the high amperage, low voltage type. Excellent results in annealing one size of tube to a desirable degree of softness has been obtained by passing a current of 1500' amperes through the tube for a few seconds; and a tube of smaller size required only 1600 amperes to pass through it for the same number of seconds with the same degree of annealed softness in each case.

Fig. 2 shows a modified disclosure wherein automatic controls are provided for inserting the tube to be treated in position, closing of the cir- 4 cuit through the tube, applying the annealing current for a desired time interval, then opening the tube circuit and then removing the tube for replacement by another one. The parts are interlocked for insuring the proper sequence of steps. The parts corresponding to those of Fig. 1 are designated by the same reference characters.

The tube 4 is in position after being annealed and is supported on a contact base I2 which has an upward projecting portion In fixed within the lower end of the tube. A clamp I22) surrounds the outside of the lower end of the tube and is adapted to firmly clamp the end of the tube against the projection 12a when the clamp is compressed. Above the tube is shown the other electrode or contact l3 shaped within to conform with the shape of the top of the tube and carries a compressible clamping ring l3a for embracing the outside of the top portion. The upper contact is carried by a conducting rod I4 which projects upwardly and is electrically connected by the flexible lead I ia to the supply line 2a. A spring i5 is secured to the upper end of the rod M, the spring being fixed at its upper end for biasing the conductor l4 and contact 13 upwardly to the position shown.

A pivoted lever is has one end slidably embracing the conductor I i. A spring H is imposed between the underside of the end of the lever l6 and the contact 13 and encircles the rod M. The opposite end of the lever 15 carries a pair of yieldable contacts [8 and l8a.. When the lever is turned in a counter-clockwise direction from the position shown, the contact I8 will first engage a fixed contact l9 and upon further movement of the lever the contact ifia will engage a fixed contact l9a.

The contact l9a is connected to one end of the relay winding 6, the other end thereof being connected to a fixed contact 28 which is adapted to be engaged by a pivoted conducting element 20a which in turn is connected to the line 8 of the auxiliary control source '1. The contact 20a is connected to a plunger rod Zeb which passes freely through a. fixed support 290. A compression spring 2| encircles the rod 2% and is secured at one end to the fixed support 260. The other end of the spring engages a block or plate 21a carried by the end of the rod 291) and is adapted to be engaged by the tube 4 when the latter is in position to be annealed.

A slowly turning motor 9 i supplied from the source 1 and drives a cam 22 mounted on an extension of its shaft or may drive the cam through reduction gearing. This cam has a projecting portion which is shown in engagement with a pivoted contact element 23 which in turn is in engagement with a fixed contact 23a. When the cam is turned in the direction of the arrow, its projection engages another pivoted contact element 24! which is then moved into engagement with the fixed contact 24a. Further movement of the cam will raise the right-hand end of the lever l6 and cause its contact i8 to first engage the fixed contact l9 and subsequently cause the contact 13a to engage the fixed contact I911. The contacts I8 and Ida are connected to one side Ba of the auxiliary source 1.

The contact I9 is electrically connected to one terminal of a relay winding 25, the other terminal of which is connected to the line 8. When this relay is energized it attracts its pivoted armature and actuates the red 2501, to engage the clamp 13a when in position around the tube for making a firm engagement therewith. The contact 19 is also electrically connected to the tear" minal of a relay winding 26, the other terminal of which is connected to the line 8. "This relay when energized attracts its pivoted armature and causes the rod 26a extending therefrom to engage the clamp 2b for firmly holding the lower end of the tube against the contact portion 12a.

Fig. 3 is a plan view of one form of clamp applied to the upper and lower ends of the tube. 2

It comprises two semi-circular bands a and b hinged together at c and having projecting portions d opposite thereto. A spring c between the projecting portions tends to open the bands somewhat, as indicated by the dotted lines, for reception of the ends of the tube 4. The lower half of the clamp of Fig. 3 'is -fixed to and in electrical connection with the base 12 in one case and electrode [3 in the other case. A flexible electrical connection extends-around the hinge c for passing current from the fixed half of the clamp to the movable half. When the ends of the rods 25a and 26a respectively engage the movable ends of the half-rings b they compress the springs e and make 'a firm clamping electrical contact with the tube ends.v

When the cam 22 moves the contact element 23 against the fixedcontact 23a it energizes a relay winding 2'! which has one terminal thereof connected to the contact 23a, the other terminal being connected to the line 8. When this relay is energized it attracts its pivoted armature and thereby moves the rod 27a into engagement with the tube for moving it out of its annealing position. When the cam 22 causes the contact element 24 to engage the fixed contact 24a, a relay having a winding 28 is energized and thereupon attracts its pivoted armature and actuates a rod 28a for moving another tube la into position to be annealed, the other terminal of the winding Ml-being connected to the line 8.

The connection of the parts not already par- 'ticularly referred to will be understood from a description of the mode of operation. The parts are shown in their relative positions immediately after the tube 4 has been annealed. At this time the cam 22 has moved the contact element 23 into engagement with the contact 23a which energizes therelay 21 by a circuit from the line 8 through the relay and through the contacts 23a and 23 to the line. 80.. This causes the rod 21a to be moved into engagement with the tube 4 and push it out of position so that another tube may be moved in its place. Although Fig. 2 shows the relay 2'! and its *rod 210. in the plane of the paper, it would be physically located at right-angles thereto. The removal of the tube permits the spring 2! to expand and move the rod 20b and the contact element 20a out of engagement with the fixed contact 20.

When the cam 22 has moved from the position shown so that its projection engages the contact element 24 and which then engages the fixed contact 24a, the relay 28 is energized by a circuit from line 8 through the relay to the contact 24a and contact element 24 to the line 8a. The relay 28 then actuates its rod 28a to move another tube la from a supply line of the tubes to the annealing position. The diagram of Fig. 2 shows the relay 28 engaginga tube at some distance from the left of the annealing position for clarity of disclosure. When the tube is moved into position by the relay 28 it is pushed against the plate Zia which presses the spring 2! and causes the rod 26b to move the contact element 280. against the contact 2D. This is an interlocking arrangement with reference to the relay 6 which prevents the latter from being energized unless the tube is in the annealin'g position. Further movement of the cam would permit the contact 24 to separate from its fixed contact which deenergizes the relay 28 and permits rod 28a to be withdrawn and the tube will remain in position and maintain the spring 2| compressed.

Further movement of the cam will raise the right-hand end of the lever l6 and cause the lefthand end to compress the spring l l and the contact I3 to engage the upper end of the tube. This causes a shunt circuit around the closed switch 522 by a path from the supply line 2a through the spectively which causes them to firmly embrace the outside end portions of the tube and thereby secure a good electrical contact of the electrodes with the tube. Further elevation of the righthand end of the lever it by the cam 22 results in the contact I-8a engaging the fixed contact I Sa. This closes a circuit through the relay 6 by a path from the auxiliary source line 8a through contacts 18a and [9a, then through the relay winding 5, then through contacts 29 and 26a, which are now closed, to the line 8. This energization of the relay '6 causes the contact element 6b to separate from the contact Ga and thereby pass the full load current through the tube. This condition is maintained by the cam 22 a few seconds or long enough to bring the tube to the annealing temperature, after which the continued movement of the cam permits the right-hand end of the lever It to move downwardly and first separate the contact lSa from contact I911. This deenergizes the relay 8 which recloses the shunt around the tube circuit which relieves the tube from the load current. Further movement of the cam next permits the contact l8 to separate from the contact 19 which results in deenergizing the relays Z5 and 2E and this removes the clamping pressure of the clamps l3a and i217. Further movement of the cam permits the contact 13 to be raised by the spring 15 from the top portion of the tube. Continued movement of the cam results in its arriving at the position shown in Fig. 2 with the contact 23 engaging the contact 23a which, as already explained, energizes the relay 2? for removing the tube from its annealing position. This sequence of controls is repeated with each revolution of the cam 22.

It is apparent by these automatic controls that the tube to be annealed is first placed in position and an interlocking switch controlled thereby for preventing the excitation of the relay 6 and its contact element 6b from opening the load circuit until the tube is placed in the annealing position,

then the tube is placed in a shunt circuit around the load switch 6b and the electrodes clamped at opposite ends of the tube, then the load switch is opened for passing the annealing current through the tube, then the load switch is reclosed for shunting the load current away from the tube, then the clamping rings at the opposite ends of the tube are released, then the upper electrode is raised from the tube which action is followed by the excitation of the relay for removing the tube from its annealing position. The time of each revolution of the cam 22 may, of course, becontrolled by adjusting the speed of the timing motor ,9; and the contour of the cam 22 may be changed as desired for controlling the time intervals during which the contacts controlled thereby are maintained closed for adaptation to particular conditions and requirements.

cally indicated, it will be understood that they may be of any other desirable type such as the solenoid, or contactor type. Also, although the controlling relays are shown directly controlling the parts shown, they may, of course, control interposed parts for accomplishing the desired results.

Although particular embodiments of this invention are disclosed for annealing aluminum tubes, it will be understood that various other devices of different forms and of different metals or compositions may be annealed in the same manner and by utilizing the same method with out departing from the scope of the invention.

I claim:

1. Controlling apparatus for electrically annealing a metal device comprising a supply circuit, a load connected thereto, said device being connected in series with said load, a switch in series with said load and in shunt to saiddevice, and timing means for controlling the opening of said switch for a predetermined time interval and then the reclosing of said switch.

2. Controlling apparatus for electrically annealing a metal device comprising a supply circuit, a load connected thereto, a switch for connecting said device in series with said load, a second switch in series with said load and in shunt to said device and said first named switch, a relay for controlling the closing and opening of ,said first named switch, a second relay for controlling the opening and closing of said second named switch, and timing means for controlling said relays for first closing said first named switch, then controlling the opening of said second named switch for a predetermined time interval and then closing said second named switch and then opening said first named switch.

3. Controlling apparatus for electrically annealing a metal device comprising means for passing annealing current through said device, i

a switch for by-passing said current from said device, and timing means for opening said switch for a predetermined time interval and then 'closing said switch. I

4. Controlling apparatus for electrically annealing a metal device comprising means for passing annealing current through said device, a switch for by-passing said current from said device, a relay for controlling said switch, and a timer for energizing said relay for opening said switch for a'predetermined time interval and then deenergizing said relay for causing the closing of said switch.

5. Controlling apparatus for electrically annealing a metal device comprising a supply circuit, a load connected thereto, a movable element for connecting said device in series with said load, a switch in series with said load and in shunt to said device, and means for first actuating said movable element for connecting said device in the load circuit, then opening said switch for a predetermined time interval, then closing said switch and then actuating said movableelement for disconnecting said device from the load circuit,

6. Controlling apparatus for electrically annealing a metal device comprising a supply circuit, a load connected thereto, a movable element for connecting said device in series with said load, a switch in series with said load and in shunt to said device, a relay for controlling the ejecting of said device from annealing position, and timing means for first actuating said movable element for placing said device in circuit with said load, then opening said switch for a predetermined time interval, then closing said switch, then disconnecting said device from the load circuit and then energizing said relay for ejecting said device from its annealing position.

7. Controlling apparatus for electrically annealing a metal device comprising a supply circuit, a load connected thereto, a movable element for connecting said device in series with said had, a switch in series with said load and in shunt to said device, a relay for controlling the ejecting of said device from annealing position, a second relay for controlling the placing of another such device in annealing position, and timing means for first actuating said movable element for connecting said device in the load circuit, then opening said switch for a predetermined time interval and then closing said switch, then removing said device from the load circuit, then energizing said first named relay for ejecting said device from its annealing position and then energizing said second named relay for placing another such device in annealing position.

8. Controlling apparatus for electrically annealing a metal device comprising a supply circuit, a load connected thereto, a movable element for connecting said device in series with said load, a switch in series with said load and in shunt to said device, a relay for controlling the movement of said switch, a second switch connected in series with the winding of said relay only when said device is in annealing position, and timing means for first actuating said movable element for connecting said device in series with the load, then energizing said relay for controlling the opening of said switch for a predetermined time interval and then closing said switch and then disconnecting said device from said load circuit.

WALTER. J. WELENBORG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,606,746 Candee Nov. 16, 1926 1,647,296 Jefieries Nov. 1, 1927 2,016,369 Hoopes Oct. 8, 1935 2,105,105 Zimmerman Jan. 11, 1938 2,400,472 Strickland, Jr May 14, 1-946 

